Solventless paint composition of resins suitable for application as a hot melt

Abstract

The present invention discloses solventless composition suitable for application as a hot melt to a substrate, said composition comprising a mixture or alloy of resins, selected such that the averaged glass transition temperature (Tg) of the combined unreacted resins is greater than -30° and less than +60° C. The melt viscosity of the unreacted resins are selected so that the combined resin mix has a melt viscosity of from about 0.05 to 25 Poise when measured at 180° C. and at a shear rate of 10,000 Hz.

What is claimed is: 
     
       1. A thermosettable paint composition suitable for application from a solid block thereof as a hot melt to a substrate heated to a temperature which is hot enough to melt a surface portion of said solid block upon contact therewith, said composition comprising: a pigment; and   a thermosettable mixture of resins, having an averaged glass transition temperature (Tg) of greater than -30° C. and less than +60° C. and having a melt viscosity of from about 0.1 to 12 poise when measured at 180° C. and at a shear rate of 10,000 Hz;   wherein said mixture of resins comprises: a first resin having a glass transition temperature T g  of greater than +20° C., and   a second resin having a glass transition temperature T g  of below +20° C. and a melt viscosity of 0.1 to 7 poise when measured at 180° C. and at a shear rate of 10,000 Hz,     wherein said pigment is dispersed in said first resin and this dispersion is admixed with at least said second resin to make said solventless paint composition.   
     
     
       2. A method of manufacture of a thermosettable solventless paint composition, having the ability to be applied as a hot melt from a solid block comprising said composition onto a substrate in contact with said block which substrate has been heated to a temperature hot enough to melt a surface portion of said solid block within the time that said substrate is in contact with said block, comprising the steps of: (i) selecting a first resin having a glass transition temperature (T g ) greater than +20° C.,   (ii) selecting a second resin having a glass transition temperature (T g ) less than +20° C. and a melt viscosity of 0.1 to 7 poise when measured at 180° C. and at a sheer rate of 10,000 Hz, wherein at least one of said first and second resins is thermosettable.   (iii) dispersing a pigment in the first resin to form a pigmented first resin, and   (iv) combining the pigmented first resin and the second resin in proportions such that the glass transition temperature (T g ) of the combined mixture of resins is greater than -30° C. and less than ±60° C., and such that the combined mixture of resins has a melt viscosity of about 0.1 to 12 poise when measured at 180° C. and at a shear rate of 10,000 Hz to thereby form said solventless paint composition.   
     
     
       3. A solventless thermosetting paint composition suitable for application as a hot melt to a substrate, said composition comprising: a pigment; and   a mixture of resins having an average glass transition temperature (Tg) greater than -30° C. and less than +60° C. and having a melt viscosity of from about 0.05 to 25 Poise when measured at 180° C. and at a shear rate of 10,000 Hz;   wherein said mixture of resins comprises: a first resin having a glass transition temperature (Tg) of greater than +20° C., and   a second resin having a glass transition temperature Tg of below +20° C. and a melt viscosity of 0.1 to 7 Poise when measured at 180° C. and at a shear rate of 10,000 Hz,     wherein said pigment is dispersed in said first resin and this dispersion is admixed with at least said second resin to make said solventless thermosetting paint composition.   
     
     
       4. A composition according to claim 1 wherein one of the resins has a Tg of above 30° C. and less than 110° C. and another has a Tg of below 5° C. and above -100° C. 
     
     
       5. A composition according to claim 4 wherein one of the resins has a Tg of greater than 30° C. and less than 70° C. and another resin has a Tg of below 5° C. and above -60° C. 
     
     
       6. A composition according to claim 1 wherein the combined unreacted resins have an averaged Tg of from -10° C. to +40° C. 
     
     
       7. A composition according to claim 1 wherein the pigment is dispersed in a resin component having a Tg of above 20° C. and a viscosity greater than 6 P at 180° C. 
     
     
       8. A composition according to claim 1 wherein the resins are selected from the group consisting of polyesters, silicone modified polyesters, acrylic, alkyd, epoxy, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, fluorinated polymers, chlorinated polymers, and urethane resins. 
     
     
       9. A composition according to claim 8 wherein at least one of the resins is a polyester resin. 
     
     
       10. A method according to claim 2 wherein the step of dispersing is conducted in an extruder. 
     
     
       11. A method according to claim 10 wherein the extruder is a multi port extruder and wherein the first resin is admitted at a first port and silica is introduced to the resin at a second port downstream from the first port. 
     
     
       12. A method according to claim 11 wherein silica is combined with the second resin prior to combination of the second resin with the first. 
     
     
       13. A method according to claim 2 wherein the first resin has a Tg of above 30° C. and below 110° C. 
     
     
       14. A method according to claim 2 wherein the first resin has a melt viscosity of greater than 6 P at 180° C. 
     
     
       15. A method according to claim 2 wherein the second resin has a Tg of below 5° C. and above -60° C. 
     
     
       16. A method according to claim 2 wherein the first resin is selected from the group consisting of polyesters, silicone modified polyesters, acrylic, alkyd, epoxy, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, fluorinated polymers, chlorinated polymers, and urethane resins. 
     
     
       17. A method according to claim 2 wherein the second resin is independently selected from the group consisting of polyesters, silicone modified polyesters, acrylic, alkyd, epoxy, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, fluorinated polymers, chlorinated polymers, and urethane resins. 
     
     
       18. A composition according to claim 3 wherein the first resin has a (Tg) of from 20° C. to 70° C. and a viscosity of from 5 to 25 Poise when measured at 180° C. and at a shear rate of 10,000 Hz. 
     
     
       19. A composition according to claim 3 wherein the second resin has a viscosity of from 0.2 to 4 Poise when measured at 180° C. and at a shear rate of 10,000 Hz. 
     
     
       20. A composition according to claim 18 wherein the first resin has a viscosity of from 6 to 12 Poise when measured at 180° C. and at a shear rate of 10,000 Hz. 
     
     
       21. A composition according to claim 3 wherein the resins are selected from the group consisting of polyesters, silicone modified polyesters, acrylic, alkyd, epoxy, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, fluorinated polymers, chlorinated polymers, and urethane resins. 
     
     
       22. A composition according to claim 21 wherein the first or second resin is a polyester resin. 
     
     
       23. A method of manufacture of a solventless thermosetting paint composition, comprising the steps of: (i) selecting a first resin having a glass transition temperature (Tg) greater than +20° C.,   (ii) selecting a second resin having a glass transition temperature (Tg) less than +20° C. and a melt viscosity of 0.1 to 7 Poise when measured at 180° C. and at a shear rate of 10,000 Hz,   (iii) dispersing a pigment in the first resin to form a pigmented first resin, and   (iv) combining the pigmented first resin and the second resin in proportions such that the glass transition temperature (Tg) of the combined mixture of resins is greater than -30° C. and less than +60° C., and such that the combination mixture of resins has a melt viscosity of about 0.05 to 25 Poise when measured at 180° C. and at a shear rate of 10,000 Hz to thereby form said solventless thermosetting paint composition.   
     
     
       24. A method according to claim 23 wherein the first resin has a viscosity of from 5 to 25 Poise when measured at 180° C. and at a shear rate of 10,000 Hz. 
     
     
       25. A method according to claim 24 wherein the first resin has a viscosity of from 6 to 12 Poise. 
     
     
       26. A method according to claim 23 wherein the second resin has a viscosity of from 0.2 to 4 Poise when measured at 180° C. and at a shear rate of 10,000 Hz. 
     
     
       27. A method according to claim 23 wherein the step of dispersing is conducted in an extruder. 
     
     
       28. A method according to claim 27 wherein the extruder is a multi-port extruder and wherein the first resin is admitted at a first port and silica is introduced into admixture with the first resin at a second port downstream from the first port. 
     
     
       29. A method according to claim 28 wherein said silica is combined with the second resin prior to combination of the second resin with the first resin. 
     
     
       30. A method according to claim 23 wherein the first resin has a Tg of above 30° C. and below 110° C. 
     
     
       31. A method according to claim 23 wherein the second resin has a Tg of below 5° C. and above -60° C. 
     
     
       32. A method according to claim 23 wherein the first resin is at least one member selected from the group consisting of polyesters, silicone modified polyesters, acrylic, alkyd, epoxy, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, fluorinated polymers, chlorinated polymers, and urethane resins. 
     
     
       33. A method according to claim 23 wherein the second resin is independently selected from the group consisting of at least one of polyesters, silicone modified polyesters, acrylic, alkyd, epoxy, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, fluorinated polymers, chlorinated polymers, and urethane resins. 
     
     
       34. A solventless thermosetting paint composition suitable for application as a hot melt to a substrate, said composition comprising a mixture of resins having an average glass transition temperature (Tg) greater than -30° C. and less than +60° C. and having a melt viscosity of from about 0.1 to 12 Poise when measured at 180° C. and at a shear rate of 10,000 Hz, wherein at least one of the resins has a Tg of below 20° C. and a viscosity of from 0.1 to 7 Poise when measured at 180° C. and at a shear rate of 10,000 Hz. 
     
     
       35. A composition according to claim 34 wherein at least one resin of the mixture has a Tg of from 20° C. to 70° C. 
     
     
       36. A composition according to claim 34 wherein the resin having a Tg below 20° C. has a viscosity of from 0.2 to 4 Poise when measured at 180° C. and at a shear rate of 10,000 Hz. 
     
     
       37. A composition according to claim 35 wherein the resin having a Tg of from 20° C. to 70° C. has a viscosity of from 6 to 12 Poise when measured at 180° C. and at a shear rate of 10,000 Hz. 
     
     
       38. A composition according to claim 35 wherein the resin having a Tg of from 20° C. to 70° C. has a pigment dispersed therein. 
     
     
       39. A composition according to claim 34 wherein the resins are independently selected from the group consisting of at least one member selected from polyesters, silicone modified polyesters, acrylic, alkyd, epoxy, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, fluorinated polymers, chlorinated polymers, and urethane resins. 
     
     
       40. A composition according to claim 39 wherein at least one of the resins is a polyester resin. 
     
     
       41. A method of manufacture of a solventless thermosetting paint comprising the steps of: (i) selecting a first resin having a glass transition temperature (Tg) greater than +20° C.,   (ii) selecting a second resin having a Tg less than +20° C. and a melt viscosity of 0.1 to 7 Poise when measured at 180° C. and at a shear rate of 10,000 Hz, wherein at least one of said resins is thermosetting;   (iii) dispersing a pigment in the first resin to form a pigmented first resin, and   (iv) combining the pigmented first resin and the second resin in proportions such that the Tg of the combined mixture of resins is greater than -30° C. and less than +60° C., and such that the combined mixture of resins has a melt viscosity of about 0.01 to 12 Poise when measured at 180° C. and at a shear rate of 10,000 Hz.   
     
     
       42. A method according to claim 41 wherein the first resin has a viscosity of from 6 to 12 Poise. 
     
     
       43. A method according to claim 41 wherein the second resin has a viscosity of from 0.2 to 4 Poise. 
     
     
       44. A method according to claim 41 wherein the step of dispersing is conducted in an extruder. 
     
     
       45. A method according to claim 44 wherein the extruder is a multi-port extruder and wherein the first resin is introduced at a first port and silica is introduced into admixture with the first resin at a second port downstream from the first port. 
     
     
       46. A method according to claim 45 wherein silica is combined with the second resin prior to combination of the second resin with the first. 
     
     
       47. A method according to claim 41 wherein the first resin has a Tg of above 30° C. and below 110° C. 
     
     
       48. A method according to claim 41 wherein the second resin has a Tg of below 5° C. and above -60° C. 
     
     
       49. A method according to claim 41 wherein the first resin is at least one member selected from the group consisting of polyesters, silicone modified polyesters, acrylic, alkyd, epoxy, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, fluorinated polymers, chlorinated polymers, and urethane resins. 
     
     
       50. A method according to claim 41 wherein the second resin is independently selected from the group consisting of at least one of polyesters, silicone modified polyesters, acrylic, alkyd, epoxy, melamine-formaldehyde, urea-formaldehyde, phenol-formaldehyde, fluorinated polymers, chlorinated polymers, and urethane resins. 
     
     
       51. A paint composition as claimed in claim 1 in the form of a solid block so sized and shaped that one of said blocks is sufficient to, upon contact with a surface of a heated substrate, deposit a molten film on said substrate in an amount sufficient to be spread to cover said substrate surface. 
     
     
       52. A solid block of a thermosetting paint composition as claimed in claim 51, wherein said contact is between said block and said substrate which is moving relative to said block. 
     
     
       53. A composition as claimed in claim 8 wherein at least some of said resins are elastomers. 
     
     
       54. A method as claimed in claim 16 wherein at least some of said resins are elastomers. 
     
     
       55. A method as claimed in claim 17 wherein at least some of said resins are elastomers. 
     
     
       56. A composition as claimed in claim 21 wherein at least some of said resins are elastomers. 
     
     
       57. A method as claimed in claim 32 wherein at least some of said resins are elastomers. 
     
     
       58. A method as claimed in claim 33 wherein at least some of said resins are elastomers. 
     
     
       59. A composition as claimed in claim 39 wherein at least some of said resins are elastomers. 
     
     
       60. A method as claimed in claim 49 wherein at least some of said resins are elastomers. 
     
     
       61. A method as claimed in claim 50 wherein at least some of said resins are elastomers.